: Proteomics Shared Resource (PSR) The goal of the Proteomics Shared Resource (PSR) is to enable University of Arizona Cancer Center (UACC) investigators to identify and characterize proteins and peptides and their modifications using modern proteomics methods. The PSR provides twenty distinct proteomics services that enable the systematic analysis of protein identification and characterization, including quantification and mapping modifications, via state-of-the-art modern mass spectrometry and peripheral instrumentation. PSR equipment includes an array of proteomics instrumentation including 2D and 3D quadrupole ion traps, hybrid mass analyzers (Waters QTOF Premier and the AB Sciex 4000 QTRAP), an AB Sciex triple quadruple mass analyzer and MALDI-TOF mass spectrometer, and a linear quadrupole ion trap Orbitrap Velos high-resolution and high-accuracy mass spectrometer system with CID/HCD/ETD. All mass analyzers are full LC-MS/MS systems, with the exception of the MALDI-TOF system. A comprehensive set of proteomics services are offered to UACC members at very affordable rates. Free-of-charge unlimited assistance and consultation with experimental design, planning, data mining, and data interpretation are also offered to UACC members. The PSR staff provides training for users when requested.